TFF1 and Barrett esophagus: Expression of mRNA for columnar and intestinal epithelium-specific genes such as KRT7, KRT8, KRT18, KRT20, TFF1, TFF2, TFF3, VIL1, MUC2, MUC3A/B, MUC5B, MUC6, MUC13 was significantly upregulated in human BE biopsies when compared with gene expression in samples collected from normal squamous epithelium in at least one out of three analyzed databases (p < 0.05, Table 1).